The invention relates to a new process for the production of 17.alpha.-ethinyl-17.beta.-hydroxy-18-methyl-4,15-estradien-3-one (gestodene) and the new intermediate compounds for this process. Gestodene is an intensely active gestagen that can be used, for example, as a gestagen component in preparations for contraception (U.S. Pat. No. 4,081,537).
Several processes for the production of gestodene are already known. However, the introduction of the .DELTA..sup.15 double bond is a problem that has not yet been solved satisfactorily. Chemical dehydration methods result in low yields since the 18-methyl group inhibits the reaction (German laid-open specification No. 24 39 082). Enzymatic dehydration catalyzed by organisms is characterized by high synthesis costs (German laid-open specification No. 24 56 068).
In Tetrahedron 42 (1986) 2971-2977, a process for dehydrating ketones by palladium-catalyzed reactions of enolacetates with allyl carbonates is described.